Hong Kong air pollution

Hong Kong pollution soars as city experiences smoggiest day of the year

Index equals previous smoggiest day as authorities say pollution will linger over weekend

PUBLISHED : Friday, 19 September, 2014, 1:22pm
UPDATED : Monday, 27 April, 2015, 3:29pm

Hongkongers awoke to one of the smoggiest days of the year on Friday as weather conditions left the city choking on pollution that represented a 'serious risk' to health. 

At 4pm, all 15 monitoring stations operated by the Environmental Protection Department (EPD) were recording "very high" or "serious" levels of pollution, the most severe category. All but two general stations and all roadside stations were at level 10+, the highest level on the government's Air Quality Health Index (AQHI), introduced last year. The PM2.5 level was over 160 for much of the day, more than double the government's limit of 75.

Health officials advise that members of the public "reduce to the minimum" the amount of time they spend outside, particularly in areas of heavy traffic, when the pollution level is “serious".

Employers of outdoor workers are also advised to take appropriate procedures to reduce the risk to their employees.

The EPD last year replaced its old pollution index called API with the air quality health index, which calculates the hospital admission risks brought about by air pollutants. The AQHI index has five categories from “low”, “high” and “very high” to “serious”., which monitors air quality in cities around the world, recorded an air quality index (AQI) of 163 for Hong Kong as a whole on Friday morning, with Mong Kok, Kwun Tong and Central particularly polluted.

"The intense sunshine and high temperature have enhanced photochemical smog activities and formation of ozone during the daytime, resulting in higher pollution levels," the EPD said in a press release. "Light winds in the urban areas hinder the effective dispersion of the pollutants at street level leading to higher than normal nitrogen dioxide level."

According to the Hong Kong Observatory, there will likely be a few showers today and over the weekend, but the EPD said it expected pollution levels will remain higher than normal for the next few days.

The last time the AQHI monitoring stations hit “serious” was on June 8 – which was Hong Kong’s smoggiest day of the year so far.